Methodology
Our ratings are calculated by averaging the expert ratings available for a particular product. We first normalize each expert rating so that they all have the same scale. We have chosen a scale of 1-100 for normalizing the expert ratings and for our overall ratings. In other words, if an expert has a rating scale of 1-10 then we simple just multiply the original rating by 10. If another expert has a rating scale of 1-5 stars then we multiply the original rating by 20.
Equal Weight
We don't value more the ratings of any particular source. In other words we do not weight more the rating of a particular source. However, we are careful to include the expert ratings of those sites/persons that have established a reputation in rating products for that particular category.
User Comments but not User Ratings
We believe that user reviews are very valuable as a research tool. However, most regular users may have limited experience with a particular product and therefore the ratings they may assign may not be representative of the overall quality of the product.
For example, if a person has only bought one digital camera the rating this person may assign has little point of comparison. This is why we don't use user ratings in calculating our overall rating.
Time Considerations
Consumer electronics are constantly improving. The top rated digital camera today is much better than the top rated digital camera from 5 years ago. It is for this reason that you can't compare product ratings without taking into consideration the time when the product was released. It is for this reason that when comparing products within a particular category we group products released within the same time frame.